1. The Field of the Invention
The present invention relates to fittings for connecting pipes or tubing together. More particularly, the present invention relates to a ramp-lock quick-connect fitting device for coupling a pipe, such as a quartz pipe of a quartz tank, to another pipe or tube such as used to convey a liquid into or out of the quartz tank during semiconductor device fabrication processes.
2. The Relevant Technology
During fabrication of semiconductor devices from silicon wafers, various processes are carried out prior to cutting the wafer into individual chips for packaging. At certain stages during fabrication of some semiconductor devices, wet fabrication processes are used such as wet etches. The chemicals used during these wet processes such as acids or alkalies reside in quartz tanks that are resistant to corrosion and high heat. Quartz tanks are also used as part of a system for cleaning silicon wafers, or in a chemical distribution system of a semiconductor production line.
A quartz tank generally includes a quartz outlet/inlet pipe that is in communication with a synthetic resin tube used to convey chemicals into or out of the quartz tank. Quartz pipes are utilized for distributing chemicals since such pipes have high chemical resistance properties, pressure tightness, heat resistance, and the like. Various fittings or pipe joints have been used to connect quartz pipes with synthetic resin tubes.
For example, U.S. Pat. No. 5,516,159 to Hirakawa et al. discloses a quartz pipe joint including a joint body having a pipe receiving portion into which a quartz pipe is to be inserted, a ring-like sealing member held at the pipe receiving portion of the joint body, and a deformable lock ring. A nut to be externally fitted onto the quartz pipe and connected to the joint body is also provided, along with a pressing piece disposed in the nut.
A problem with conventional quartz pipe fittings is that they are difficult to manipulate during routine maintenance procedures, both during assembly and disassembly of the fittings. Conventional quartz pipe fittings are particularly difficult to assemble and disassemble in cramped areas, such as areas underneath quartz tanks where the quartz pipe fittings are located and which are difficult for maintenance personnel to access. These areas typically have a hot acid environment, adding to the difficulties which maintenance personnel have in performing maintenance procedures with conventional fittings in place. The threads on conventional fittings are typically very fine, making it difficult to make connections between the quartz pipe of the tank and other tubing. In addition, conventional quartz pipe fittings often leak and come apart, adding to the time needed to perform repair and maintenance procedures.
While there are several quick-connect type fittings available, such as quick-connect pneumatic fittings and several types of water fittings, none of these are adapted for application to a quartz tank and none can be placed between existing fittings in a piping system without modification of such fittings in some way.
Accordingly, improved fitting devices are needed which allow for easy maintenance of quartz pipe joint areas underneath quartz tanks and in other piping systems.
The present invention is directed to a ramp-lock quick-connect fitting device providing fluid communication between tubular members such as a pipe and a flexible tube. The quick-connect fitting of the invention is adapted to be placed between conventional type fittings on piping systems typically used in industry such as quartz pipes and synthetic resin tubes used in chemical processing systems for semiconductor device fabrication. The device of the invention provides a quick connect/disconnect coupling for conventional fittings that are otherwise difficult to assemble and disassemble. The device of the invention thus converts the connection of a conventional fitting into a quick connect/disconnect coupling.
In one embodiment of the invention, the quick-connect fitting includes a first coupling member having a pipe receiving section adapted to receive a conventional fitting on a pipe, and a ramp support section with a pair of external spiral ramps formed therearound. The quick-connect fitting also includes a second coupling member that sealingly engages the first coupling member. An extension portion of the second coupling member is adapted to receive a conventional fitting on a tube. A locking collar is movably engaged with the second coupling member and has a pair of lock members disposed on an interior surface of the collar. The lock members slidably engage with the spiral ramps when the collar is rotated around the ramp support section of the first coupling member. The lock members can be a pair of buttons which provide a ramp-to-button coupling mechanism in the quick-connect fitting. In another embodiment, a pair of internal spiral ramps can be formed on the interior surface of the collar which provide a ramp-to-ramp coupling mechanism.
When the quick-connect fitting device of the invention is used in piping systems for transporting strong chemicals, it is preferable to construct the components of the fitting device with materials that are chemically resistant to strong acid, strong alkali, or the like. Suitable materials having chemical resistance that can be utilized to fabricate the components of the fitting device include synthetic resins such as fluorocarbon or fluoropolymer materials. For example, the first and second coupling members described above, which may be exposed to corrosive chemicals during use, can be formed from chemically resistant fluorocarbon materials.
Other embodiments of the quick-connect fitting of the invention include similar components as described above, with the addition of other components to make the quick-connect fitting compatible with certain conventional fittings. In one alternative embodiment, a tube member is disposed in the pipe receiving section of the first coupling member, with the tube member capable of extending into a pipe with a conventional fitting. In another alternative embodiment, the pipe receiving section of the first coupling member includes a collar member disposed in a threaded cavity portion that is compatible with a different conventional pipe fitting.
The quick-connect fitting device of the invention has the advantage of being able to be placed between existing conventional fittings used in plumbing apparatus, eliminating the need for adapting or retrofitting the conventional fittings in order to install the quick-connect fitting of the invention. In addition, the quick-connect fitting allows for easier maintenance of piping systems, since no tools are needed to connect and disconnect the quick-connect fitting of the invention.
These and other aspects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.